Automatic paper reel joining mechanism



Jan. 25, 1966 E. M. MUTH 3,231,211

AUTOMATIC PAPER REEL JOINING MECHANISM Filed Feb. 2, 1961 2 Sheets-Sheet 1 Jan. 25, 1966 E. M. MUTH AUTOMATIC PAPER REEL JOINING MECHANISM 2 Sheets-Sheet 2 Filed Feb. 2, 1961 To Slur Rce/ Roah'qg Mofor m MQ United States Patent v. 3 1 AUTOMATIC PAPER REEL JOINING MECHANISM Engelbert M. Math, Wurz hnrg, Germany, assignor to Schnellpressenfabrik Koenig dz Bauer Alrtiengesellsch'aft, Wurzburg; Germany, a corporation of Germany Filed Feb. 2-, 1961, Ser. No. 86,755 I Claims priority, application Germany, Feb. 17, 1960,

, Sch 27,438 3 Claims. (Cl. 242--58.2)

This invention relates to improvements in web fed rotary printing presses and other uses of fully automatic pa er" joining mechanism for joining a web of a new reel on a reel star with the expiring web.

The improvement relates topap'er reel change devices wherein automatic control of the same is put into effect by a control impulse which is dependent on the diameter of the expiring reel.

These devices especially comprise reel joining mechanisrns, the automatic'performance of which is initiated by a comparison of the number of revolutions of the expiring reel and of the rotary press to which the web is fed.

In an existing device of this kind counter-connected electric generators, so-cal'led tachometers or equivalent devices, are driven by the expiring reel in dependence on the corresponding reel diameter and invariably corre- 'sponding to the Web speed. The reel star rotation is then started ,when the voltages or speeds respectively of the generators are equal.- This results in a special disadvanta'ge in that the rotation of the reel star is initiated when the expiring reel has reached a predetermined diameter, independently of the speed of the press. Thisd-iameter must therefore be set for maximum speed of the press. This means that, if the reel change is started at any press speed and is bound to come to anend within a fixed period of time, the waste paper remaining on the expiring reel will depend on the press speed, i.e. being dilferent according to the press speed prevailing. If, however, the smallest possible amount of waste paper is to remain on the expiring reel even at low speeds, the reel star must stay in its pasting position for a comparatively longer period of time ,until the pasting process, including control of brushand web severing knife, can be performed, thus inereasingthe possibility of register errors and misprint.

To activate the brush and severing knife with this arrangement, the prior art requires a second revolution or voltage comparison between the speed measuring instruments, i e. a control device reacting twice, for rotating the reel star and again for pasting, all comprisingftwo operations. If this second comparison is left out, then there is no guarantee that there will always be an equal and very small amount of waste paper remaining on the expiring r'eelwhich results in economical paper consumption.

These disadvantages also exist in another type of existing reel changing mechanism having an automatic control through a speed comparison between the expiring reel and the pr ess as one control signal of operation and another control device which preferably is also put into action by two pre-set voltage differences. For this purpose the two electric generators are energized atapproximately equal speeds and potentiometers are used to adjust the voltage difference required for making the different relays react. Also with this mechanism the reel change is effected in two steps so that, after rotating the reel star into pasting position, only a second speed comparison will command the pasting process itself. Above all, however, the control device is activated as soon as the expiring reel is run down to a prefixed diameter, whether or not the paper speed is low or high. Thus with these devices a single operation produces equaliamounts of waste paper on the reels only if the concession is made that automatic 3,231,21 l Patented Jan. 25 1966 ice rotation of the'reel star when an expiring reel diameter is reached which is dependent on the web speed of the press, i.e. being larger or smaller depending on its speed; the control impulse being made active at a preset diiferen'ce' of rates of revolution between the expiring reel and the press.

In this way one single control impulse achieves the result that', at diflerent press speeds, approximately equal amounts of waste paper always remain on the reel, and that the whole reel change requires an approximately constant period of time which is independent of the web speed. There is no need for a second comparison and control impulse. A control device like this selects, automatically at any web speed, the reel diameter required. After having initiated the reel change the process is continuously carried out through known means. There is practically no pause between the reel star rotation and the pasting process. Smallest waste paper possible and economical paper consumption are accompanied by this simplified control device. One embodiment according to the present invention is shown by way of example on the accompanying drawings.

FIG. 1 is an elevational view of a reel change mechanism;

FIG. 2 is a diagrammatic comparison between the numbers of revolutions of the press and the: expiring reel at reel change; and

FIG. 3 is a schematic'wiring diagram of a control mechanism.

The three-armed reel star 1 with suitable motor-driven rotation is shown in pasting position. The expiring web 2 of reel 3 is to be joined to the new reel 5 which is in driven contact with endless belt 4. Belt roll 6 is driven by the press drive (not shown) via gear box 7 which also drives electric generator 8 to produce an output signal proportional to the rate of revolution of the plate cylinder or the like of the rotary press and thus proportional to the linear speed of the web as it is fed to the press. Each reel star arm carries one of the electric generators 9, 10 and 11, each generator being driven by its own reel, for instance, from the reel core, i.e. with variable speed dependent on the reel diameter. In the position shown, the two generators 8 and 9 are acting electrically in opposition. There is further the lateral swinging frame 12 in the press which carries brush 13 and severing knife 14.

i As soon as the automatic joining process is initiated by the single control impulse, the reel star 1 is brought by clockwise rotation into the position as shown in FIGURE 1. As the real star rotates, the new reel 5 is brought into driving contact with the endless belt 4 and is accelerated thereby up to the speed of web 2. Reel 5 may reach the speed of web 2 either before it reaches the position of FIGURE 1, or shortly after reaching such a position. When the reel 5 reaches this position, the frame 12 swings over against the web 2, the pasting and cutting process is performed by means of brush 13 and knife 14, and the frame 12 is swung back to its original position. The foregoing sequence,

which follows automatically from the occurrence of the single control impulse, is carried out through known means, either mechanical or electrical, with practically no pause between rotation of the reel star and the pasting operation, and the present invention is not limited to a particular mechanical or electrical means. An example of the manner in which such a sequence may be carried out is found in US. Patent No. 2,236,164 to Barber, which discloses an electrical switch means actuated by the motion of the reel star and of the new reel to energize a pair of solenoids to cause the brush and knife carrying frame to be swung into contact with the web.

According to the invention the automatic control of the pasting process is started as soon as the generators, for instance 8 and 9, being electrically in opposition are running at a pre-selected difference between their rates of revolution. Only then do the generators efiect a control impulse. The pre-selected difference of rates of revolution at which the control impulse occurs corresponds to an expiring reel diameter which is dependent on the plate cylinder circumference and on the press speed. Thus the control impulse occurs at a selected expiring reel diameter for a given plate cylinder circumference and a given press speed, and occurs at a difierent reel diameter when either the plate cylinder circumference or the press speed is varied. In this way the automatic sequence of all processes of reel change may be started by means of one single comparison between the rate of revolutions of the genelrato rs or equivalent devices. The waste paper that remains on the reels will be an equal and small amount.

The comparison between the rates of revolution of the generators may be carried through by means of value relays. It seems necessary to have the control impulse given only at a positive difference of rate of revolution between real generator 9, or 11 and the press generator 8, i.e., if the speed of the expiring reel generator is higher than the speed of the press generator. The function of the electric generators can also be accomplished by any suitable electro-magnetic or equivalent impulse counter transforming the rotation of shafts into impulses.

A single control impulse or signal may be developed according to the invention to first initiate the reel star rotation in accordance with circuit apparatus as illustrated in FIG. 3. The alternating current voltages, originating from the generators 8 and 9, 10 or 11 respectively are rectified by means of two spearate recifiers G and G Electrical controlling means are provided whenever one of the generators 9 or 10 or 11 on real star 1 is being driven by the expiring reel. Both direct current voltage from the rectifiers G and G are counter-connected and charge equal combinations of resistances P /R and P /R so that equal generator characteristics result. At the points A and B of the circuit there is originating a difference of control voltages, A being positive in comparison with B, if the generator 8 of the press is running at a higher speed than the generator 9, 10 or 11 on the reel star and vice versa. The direct current voltages are furthermore equalized by means of two capacitors C and C By means of the two control resistances P and P the voltages of the generators can further be effectively adapted. At the points A and B the control voltage for the valve T is taken. This control voltage is equalized again via the screening members R /C and R /C At the potentiometer P a positive voltage is put in series with this control voltage. This positive volt-age can anly be compensated by a negative voltage, originating in this case from generator 9 or It) or 11 at the paper reel. This compensation can occur only if generator 9, 10 or 11 at the reel is running at a higher speed than the generator 8 of the press.

the point at which valve T discharges, and thus the amount of the difference of number of revolutions between the two generators energizing the electrical control means P can be adjusted.

The valve T being initiated, the coil of relay S is energized. It is through the connection contact ofrelay S that the motor circuit rotating the star reel is energized to start the rotation of the reel star 1.

As a further explanation of the present invention reference is made to FIG. 2 wherein the diagram illustrates the condition under which the reel star rotation for the reel change over starts, it being understood that the cycle of operation and thus the whole process of joining the reels shall always take an approximately constant period of time, and that always an approximately equal waste paper end remains after the splice. The ordinate of this diagram represents revolutions per minute n, while the abscissa represents the radius r of the expiring reel which ought to exist at reel change over to insure that equal reel ends always remain as wastepaper. The, curve n is a plot of the rate of revolution of the expiring reel and shows that at a high rate of revolution a larger padius of the expiring reel must exist while at a low rate of revolution a smaller radius must exist at the start of reel change over to obtain equal amounts of waste paper. The curve n is a plot of the rate of revolution of the press for a given circumference of plate cylinder, and shows for each press speed the corresponding radius r 'of the expiring reel which must exist at reel change over to obtain equal amounts of waste paper.

By plotting both curve n and curve n on the same diagram, it can be seen that for a selected rate of revolution 11 of the press there is a corresponding radius rof the expiring reel that will give the required point for initiation of the reel change over cycle. For this selected rate of revolution n of the press there is also a corresponding rate of revolution m of the expiring reel which requires the same radius r of the expiring reel at change over to insure equal amounts of waste paper. Therefore, when the press speed has been selected, reference to the diagram of FIG. 2 will give the radius r at which change over must occur and will also give the rateof revolution of the expiring reel (from curve n which corresponds to that radius.

Further, in FIG. 2 the hatched area-F shows the range of the actual rates of revolution of a usual rotary press and an expiring reel. The dash-dotted line K represents the curve of rates of revolution of the expiring reel for a constant difference of rates of revolution (n n with respect to curve n within the scope of the actual rates of revolution. As may be seen from lines K and n the two cunves n and n are substantially parallel over the normal range of operation.

The present invention makes use of the knowled gethat, within the practicable zone of rates of revolution of the press, the difference between the "rates of revolution of the expiring reel and of the press is independent of the speed of the press prevailing at the moment of starting the star reel rotation and is approximately constant as shown in FIG. 2. A comparison of rates of revolution between expiring reel and press is therefore sufficient to determine when reelgchange-over should occur; thus rotation of the star reel is initiated at a difference of rates of revolution characteristic of the corresponding plate cylinder circumference. As noted above, the diagram of FIG. 2 represents the rates of revolution of the press and expiring reel for a particular circumference of plate cylinder. If a different circumference is used a different set of curves is used, each set being characteristic of a plate cylinder circumference. This characteristic difference of rates of revolution alters with the plate cylinder circumference; with greater circumferences of the, plate cylinder the zone of approximate constant differences of aII rates of revolution is tending toward higher rates of revolution of the press.

By further embodiment of the present invention in presses with variable sizes, as in variable rotogravure rotaries, the full range of variability can be covered so that, with large circumferences of cylinder, the area of approximately constant differences between the rates of revolutions will be situated within the practicable rates of revolution of the press. For this purpose a constant difference between the rates of revolution corresponding to the smallest circumference of press cylinder is used for the whole range of variable sizes. In this situation when a cylinder of greater circumference is used, the electric generator or equivalent device driven via changeable gear by the press must rotate more quickly according to the increase of circumference of cylinder. Thus the difference between rates of revolution is maintained approximately constant over the full range of variable sizes. The range of operation with approximately constant difierence between rates of revolution is accordingly tending to lower rates of revolution of the press. When the difference of rates of revolution and the basic plate cylinder size are correctly chosen it is assured that, with sizes and press speeds usual in rotogravure rotaries, only one single diiference between rates of revolution is needed resulting in an economical paper consumption.

With letterpress rotaries a remarkably greater range of rates of revolution is available for the pasting process, for instance, from 12,000 up to 30,000 revolutions per hour. The full range of circumferences possible can be covered by two differences between rates of revolution. Being presses of fixed sizes, a certain practicable difference of rates of revolution can be determined for a certain cylinder circumference. In the drive of the one electric generator or equivalent device provision can be made for a corresponding step-down gearing which brings the sphere of approximate constant differences between rates of revolutions within the reach of the press rates of revolution practicable for the pasting process.

I claim as my invention:

1. In a reel-changing apparatus for use with a Web-fed rotary printing press, means for driving said press, a revolving reel star carrying a plurality of web reels, each of said reels carrying a web to be fed in succession to said rotary printing press, web joining means having a single, continuous cycle of operation for attaching the web from a new reel to the web from an expiring reel within a substantially constant time period, said web joining means including means to rotate said reel star so as to replace said expiring reel with a new reel, means for rotating said new reel, pasting and pressing means for attaching the new web to the expiring Web, severing means for cutting said expiring web, and a control apparatus for initiating the cycle of operation of said web joining means, said control apparatus comprising means connected to said press driving means for producing a first electrical signal proportional to the rate of revolution of said rotary printing press, means for producing a second electrical signal proportional to the rate of revolution of said expiring reel comparing means responsive to said first and second electrical signals for producing a single resultant output control signal when the difference between said first and second signals reaches a value predetermined for a particular plate cylinder of a rotary printing press, said value being dependent upon a constant ditierence of rates of revolutions between said expiring reei and said press, and means responsive to said output control signal for initiating the rotation of said reel star to advance said new reel and to initiate the whole web-joining cycle whereby all the operations of said web joining cycle are completed automatically and without interruption to obtain equal and very small amounts of remaining waste paper on expiring reels at any press revolution rate within the normal operating range of the press.

2. A web-joining apparatus according to claim 1 wherein said means for producing a first electrical signal comprises a first generator connected through gears to the drive means for said press and said means for producing a second electrical signal comprises a second generator connected to and driven by the expiring reel.

3. The apparatus of claim 2 wherein said comparing means responsive to said first and second electrical signals comprises first and second rectifier means connected across said first and second generators, respectively, in series opposition, the outputs of said recifiers charging equal combinations of resistors and producing across said resistors a difference control voltage, and wherein said means responsive to said output control signal comprises a discharge device, means for applying said control voltage to said discharge device to control the conduction thereof, and load means for said discharge device operative in response to the conduction of said discharge device to initiate the cycle of operation of said Web joining means.

References Cited by the Examiner UNITED STATES PATENTS 2,249,669 7/1941 Robertson 242-58.2 2,654,545 10/1953 Bennett 242-583 2,939,646 6/ 1960 Stone 242-5 8.2 2,963,235 12/1960 Pedersen et al 242-58.3 FOREIGN PATENTS 1,156,761 12/1957 France.

684,765 12/ 1952 Great Britain.

MERVIN STEIN, Primary Examiner.

LEYLAND M. MARTIN, G. F. MAUTZ,

Assistant Examiners. 

1. IN A REEL-CHANGING APPARATUS FOR USE WITH A WEB-FED ROTARY PRINTING PRESS, MEANS FOR DRIVING SAID PRESS, A REVOLVING REEL STAR CARRYING A PLURALITY OF WEB REELS, EACH OF SAID REELS CARRYING A WEB TO BE FED IN SUCCESSION TO SAID ROTARY PRINTING PRESS, WEB JOINING MEANS HAVING A SINGLE, CONTINUOUS CYCLE OF OPERATION FOR ATTACHING THE WEB FROM A NEW REEL TO THE WEB FROM AN EXPIRING REEL WITHIN A SUBSTANTIALLY CONSTANT TIME PERIOD, SAID WEB JOINING MEANS INCLUDING MEANS TO ROTATE SAID REEL STAR SO AS TO REPLACE SAID EXPIRING REEL WITH A NEW REEL, MEANS FOR ROTATING SAID NEW REEL, PASTING AND PRESSING MEANS FOR ATTACHING THE NEW WEB TO THE EXPIRING WEB, SEVERING MEANS FOR CUTTING SAID EXPIRING WEB, AND A CONTROL APPARATUS FOR INITIATING THE CYCLE OF OPERATION OF SAID WEB JOINING MEANS, SAID CONTROL APPARATUS COMPRISING MEANS CONNECTED TO SAID PRESS DRIVING MEANS FOR PRODUCING A FIRST ELECTRICAL SIGNAL PROPORTIONAL TO THE RATE OF REVOLUTION OF SAID ROTARY PRINTING PRESS, MEANS FOR PRODUCING A SECOND ELECTRICAL SIGNAL PROPORTIONAL TO THE RATE OF REVOLUTION OF SAID EXPIRING REEL COMPARING MEANS RESPONSIVE TO SAID FIRST AND SECOND ELECTRICAL SIGNALS FOR PRODUCING A SINGLE RESULTANT OUTPUT CONTROL SIGNAL WHEN THE DIFFERENCE BETWEEN SAID FIRST AND SECOND SIGNALS REACHES A VALUE PREDETERMINED FOR A PARTICULAR PLATE CYLINDER OF A ROTARY PRINTING PRESS, SAID VALUE BEING DEPENDENT UPON A CONSTANT DIFFERENCE OF RATES OF REVOLUTIONS BETWEEN SAID EXPIRING REEL AND SAID PRESS, AND MEANS RESPONSIVE TO SAID OUTPUT CONTROL SIGNAL FOR INITIATING THE ROTATION OF SAID REEL STAR TO ADVANCE SAID NEW REEL AND TO INITIATE THE WHOLE WEB-JOINING CYCLE WHEREBY ALL THE OPERATIONS OF SAID WEB JOINING CYCLE ARE COMPLETED AUTOMATICALLY AND WITHOUT INTERRUPTION TO OBTAIN EQUAL AND VERY SMALL AMOUNTS OF REMAINING WASTE PAPER ON EXPIRING REELS AT ANY PRESS REVOLUTION RATE WITHIN THE NORMAL OPERATING RANGE OF THE PRESS. 